A nodachi is a type of traditional Japanese sword characterized by its exceptionally long blade. The length of a nodachi blade can vary, but it is typically around 55 to 65 inches (140 to 165 centimeters) or even longer.

The nodachi blade is significantly longer than the blades of other Japanese swords such as the katana or tachi. It is known for its impressive reach and cutting power. Due to its extended length, the nodachi requires two hands to wield effectively.

The exact length of a nodachi blade can vary depending on the individual sword and historical context. Some nodachi blades could even exceed 70 inches (178 centimeters) in length, although such examples are relatively rare.

It's worth noting that the nodachi is a historical sword and is not commonly seen in contemporary swordsmithing or martial arts practices. Modern reproductions or interpretations of the nodachi may vary in terms of dimensions and design.

In summary, the nodachi blade is typically around 55 to 65 inches (140 to 165 centimeters) or longer. Its length and cutting power made it a formidable weapon on the battlefield. However, it's important to note that the nodachi is a historical sword and not commonly seen in modern contexts.